Classic Presentation

Classically the patient suffering from renal colic has a sudden onset of unilateral loin to groin or renal pain, is writhing in agony or restless, and is nauseated. Pain is classically colicky in nature and radiates to the scrotum and tip of the penis or labia majora.

The pain of renal colic is caused by obstruction of flow in the ureter, leading to increased wall tension in the urinary tract. Prostaglandin synthesis is increased, with the resultant vasodilatation causing a diuresis which further increases pressure. Prostaglandins may also cause smooth muscle spasm in the ureter.

There may be intervals between episodes of pain, so it can not be assumed that cessation of pain means that the stone has been passed and the episode ended.

Learning bite

Patients with renal colic that ‘has seemed to resolve’ should be imaged.
Look out for carcinoma in all age groups and aortic complications in the elderly.